1. Field of the Invention
The present invention relates to a reflection module of a lamp of a motor vehicle, more particularly one, which can be adjusted in the width of a light passage thereon such that light from a shining element (light source) of the lamp will be reflected outside from the reflection module with an upper edge thereof being in a horizontal direction to define an imaginary horizontal line called the cut-off.
2. Brief Description of the Prior Art
Early motor vehicle lamps are usually equipped with tungsten bulbs, which are being gradually replaced with LED (light emitting diodes). And, HID (high intensity discharge) lamps are getting more popular currently, which will make vehicle lamps much brighter, thus allowing the drivers to see clearly as well as making other people notice easily in the dark and dense fog.
Light from a vehicle lamp will be very dazzling, and prone to cause accidents if the light beams travel in a direction at an angle above the horizontal direction.
Therefore, the government regulation stipulates that light beams from all car lamps be directed in a direction either parallel to or at an angle below an imaginary horizontal line, which is called the cut-off.
Referring to FIG. 1, a currently existing reflection module 7 of a lamp of a motor vehicle has a cut-off, and can prevent light of the lamp from becoming dazzling. The reflection module 7 has a light blocking plate 72, and curved shade 73. The curved shade 73 is positioned around the light source 71, and has a reflection side 731. The light blocking plate 72 is positioned lower than a light source 71 of the lamp for blocking an upper portion of light reflected from the reflection side 731 of the curved shade 73; thus only a lower portion of light reflected from the reflection side 731 of the curved shade 73 will travel outside, and an upper edge of the light beams emitted from the lamp will be in a horizontal direction, which defines an imaginary horizontal line called the cut-off.
Referring to FIGS. 2 and 3, a second currently existing reflection module 8 of a lamp of a motor vehicle includes a semispherical first reflection side 81, and a second reflection side 82. The second reflection side 82 is parabola-shaped, and disposed under and connected to a lower end of the first reflection side 81 with a gate existing between the first and the second reflection sides 81 and 82. And, a light source 84 is disposed in front of the semispherical first reflection side 81. Light emitted from the light source 84 will be reflected by the first reflection side 81, and only those portions of the light that are at certain angles of reflection will travel to the second reflection side 82 through the gate 83. And, such light will be reflected to travel outside in a horizontal direction by means of the second reflection side 82.
However, the above-mentioned reflection modules of motor vehicle lamps have a common disadvantage: they are suitable for use with only a certain kind of light sources. Different kinds of light sources, e.g. Tungsten bulbs, HID lamps, and light emitting diodes, emit light beams with different angles of spread. Therefore, the manufacturers have to manufacture several different reflection modules to be suitable for different kinds of light sources, which reflection modules can be different in their light blocking plates or the width of their gates provided for light to travel through. Consequently, the total manufacturing cost will be significantly increased. And, after the light sources have been replaced with a different kind of lamps, the reflection modules will also have to be changed, incurring more expense on the consumers. Therefore, such reflection modules aren't economical to use.